Rotary cutter attachment for power units of chain saws



Oct; 22, 1957 H. D. [BELLE ETAL 2,8

ROTARY CUTTER ATTACK-DENT FOR POWER UNITS 0F CHAIN SAWS Find Out. 26, 1955 2 Sheets-Sheet 1 Oct. 22, 1957 H. D. [BELLE ETAL 2, 1

ROTARY CUTTER ATTACHMENT FOR POWER UNITS OF CHAIN SAWS Filed Oct. 26, 1955 2 Sheets-Sheet 2 V m D. Jbellg 69 2.1 30% 7M, vhf W,

United States PatentO ROTARY CUTTER ATTACHlVlENT FOR POWER UNITS OF CHAIN SAWS Howard D. Ibelle, Fitzwilliam, N. H., and Wallace L.

Smith, Southville, Mass., assignors to Lombard Governor Corporation, Ashland, Mass., a corporation of Massachusetts Application October 26, 1955, Serial No. 542,935

2 Claims. (Cl. 143-43) Our present invention relates to portable power-driven chain saw machines. It aims to provide for such machines, whether powered electrically or by an internal combustion engine, an accessory device adapting the machine for clearing brush and undergrowth, and for other such uses including the cutting of limbs, small trees and the like.

In the preferred embodiment herein illustrated the brush-cutting unit is demountably installed on a chain saw interchangeably with the chain and chain guide bar. The power saw so equipped is such as to be easily slung on and carried by an unassisted operator with both hands free for complete control of the entire device in a natural scythe-holding manner in which the operator isprotected from moving into the active saw.

The invention will be better understood from a consideration of the following specification taken in conjunction with the accompanying drawing in'which:

Fig. 1 shows a portable power-driven chain saw as fitted with the attachment and as carried in use position;

Fig. 2 is a top plan of the apparatus of Fig. 1 and illustrating more particularly the attachment of the support shaft and bearing plate, and also the arrangement of the cutter drive;

Fig. 3 is a detail view from the side and partly in section, and showing the bearing support and driving connection of the cutter shaft;

Fig. 4 (Sheet 1) shows a conventional chain saw;

Fig. 5 is an exploded view illustrating the fastening of our attachment to the frame and in lieu of the chain and cutter bar of a saw such as illustrated in Fig. 4; and

Fig. 6 shows the bearing plate.

A portable power saw such as here concerned is illustrated in Fig. 4 and there shown to comprise generally a frame 10 supporting an internal combustion-type power supply or engine 11 and fitted also with handle bar or the like supporting and manipulating means 12. The frame 10 will be understood to incorporate also a transmission housing such as shown as terminating in a plate 13 through which projects the drive shaft 14, Fig. 5, on which latter is keyed drive sprocket 15, Fig. 4. The housing plate 13 is seen to mount also the studs 16 which normally support and position the toothed work-engaging saw guide bar 17 and behind it the elongate, laterally extending chain guide plate or cutter bar 18 such as tracking the endless linked saw or cutter chain 19.

Our novel bushing attachment is seen from the several views to comprise generally a rigid, elongate support and extension shaft or tube 20. This support member 20, and similarly the attachment elements and fittings associated therewith will be understood to be of heavy metal construction such as appropriate to their use and common to portable power saw design and construction. The attachment shaft 20 is seen further and generally as adapted or fitted at one end for rigid and demountable engagement on and support from the saw frame 10, and for extension laterally thereof, and also normal to the drive shaft 14. More particularly we provide an adaptor A 2,810,409 Patented Oct. 22, 1957 ce v 5 flatted part 21b is seen further to be apertured for fitting over the studs 16 upon removal and in place of the hearing and cutter bars 17, '18, and adapted to be removably secured against the plate 13 by the similar lock nut or other fastening means 16a, Fig. 5, as may alternatively 10 be employed for retaining said bars.

Referring now more particularly to Fig. 3, the free end of the support shaft 20 terminates in and is closed by a hollow fitting or housing 22 having a tubular portion telescoping over and riveted or welded to the shaft 15 20. The housing 22 is seen further to mount interiorly and at its top and bottom shaft bearings or journals 23, 23 one of which may be removable, as with the separable support and access plate 24, for exposure of the housing carried parts. The fixed bearings 23 are seen rotatably 0 to support a vertical shaft or arbor 25 extending outwardly through and normally downwardly of the housing 22, and so as generally to clear the support shaft 20.

Various means may be provided in accordance with the invention for connecting the shaft 25 for driving from the saw power unit 11. As herein embodied the cutter drivev is seen to comprise an endless belt 26 supported through the tube 20 and wound at its inner end over a sheave or pulley 27, Fig. 5, keyed to the drive shaft 14 interchangeably with sprocket 15, Fig. 4, and there retained by the same lock nut or the like fastening means 15a, Figs. 4, 5,-as employed with said sprocket 15. At its other .or outer end the belt 26 is wound and guided over a pulley 28 keyed to shaft 25 and confined thereon between the bearings 23. It is noted in this connection that the cutter drive may variously be adjusted for desired tensioning of the belt 26, as by varying the size of one or both of the pulleys 27, 28, or by longitudinally extensible mounting of the shaft 20 similarly as the cutter bar 18, and by means conventional in the art.

Further in accordance with the invention, the vertical transverse shaft 25 mounts a horizontal laterally extending rotary cylindrical saw or cutter blade 29', which may be removably secured thereto as by lock nut or the like fastening means 30, Fig. 3. The saw blade is seen as a rigid unitary peripherally toothed member of conventional rough cut design, and which may be provided in sizes as appropriate to the work and the particular saw drive unit for and with which the attachment may be employed. It may be noted in this connection that our novel attachment has been shown to be practical for felling trees or cutting pieces up to 8 inches in diameter.

Optionally and preferably we provide also a guard plate 31, Figs. 1 and 2, which may be supported from the shaft 25 and which is seen to extend about and enclose the disengaged side or portion of the blade 29, whereby to shield the same against injury by or to the operator or other objects with which it may accidentally be brought into contact.

Our novel brush-cutting attachment comprises further means for controlling or supporting and manipulating the -.,entire portable power saw assembly in a natural scytheholding manner and so as to give the operator protection from moving into the blade. Such means may include sling, strap or the like adjustable body support means 32 which may be anchored or removably fastened to the upper machine frame 10, and which may be passed about the neck, or, preferably, over the rear shoulder and under the forward arm, Fig. 1. It will be readily appreciated that the strap 32 permits the apparatus to be slung on unassisted, and with both hands free for guiding and operating the saw.

Co-operating with the sling 32 in the bodily support and positioning of the device is a wide vertical bearing and buffer plate 33, Figs. 1, 2, and 6, which is seen as rigidly supported from the saw frame 10. The plate 33 will be understood to have configuration and contour adaptingit for Comfortable Support on and bearing 'engagement by the operators waist and thigh, as in the dotted-line illustration in Fig. 1. It is seen also to mount an outturned wing portion 33a by which it 'is constituted additionally as a leg and body shield, and whereby the saw may be given, or supported against, longitudinal as well as lateral thrust.

The support and manipulating means associated with our novel brush-cutting saw may further comprise an additional annular or other handle bar 34 rigidly or adjustably fastened'on the support shaft 20 and providing, in conjunction with the rearmost saw frame handle 12, desired wide angle support and manipulation of the attachment fitted saw.

' The advantageous use and application of our invention will be readily appreciated and from the foregoing description by those skilled in the art. Its operation will be understood to complement that of the conventional chain saw, and to greatly facilitate the felling and cutting of trees, brush, limbs and the like. It will be seen also to promote easier, safe, and less tiring cutting, particularly of standing small trees.

It will be understood that our invention is not limited to the particular embodiments thereof illustrated or described herein, and we set forth its scope in our following claims:

We claim:

1. A brush-cutting demountable attachment for the internal combustion power unit of a standard operatorportable chain saw wherein such unit has a chain-saw blade-supporting frame, comprising a rigid elongate hollow tubular shaft for support from and extension laterally of such chain-saw power-unit frame, an adapter bracket at one end of the shaft for attaching it to said frame, a rotary blade mounted at the opposite'free end of the shaft, endless belt power transmitting means housed in and supported through said shaft and adapted for connecting said blade for actuation by the power unit in the installed position of the shaft, and a supporting and manipulating handle on and surrounding the shaft for gripping at various points around it by an operator carrying the power unit and installed attachment.

2.. Abrush-cutting demountahle attachment for the internal combustion power unit of a standard operatorportable chain saw wherein such unit has a chain-saw blade-supporting frame, comprising a rigid elongate hollow tubular shaft for support'from and extension laterally of such chain-saw power-unit frame, an adapter bracket at one end of the shaft for attaching it to said frame, a rotary blade mounted at the opposite free end of the shaft, endless belt power transmitting means housed in and supported through said shaft and adapted for connecting said blade for actuation by the power unit in the installed positionof the shaft, and a bearing and shield plate attachable to such power-unit frame adjacent the V shaft adapter bracket and in radially offset relation to the shaft for aiding bodily support and manipulation of the attachment.

References Cited in the file of this patent UNITED STATES PATENTS 

